Method of preserving comestibles.



A. J. A OTITBSEN.

METHOD OF PRESBBVING GOMESTIBLBS.

APPLICATION nun NOV. 11,1912.

1,129,716. I Patented Feb. 23, 1915.

resulting tem erature, which quickly ANTON JENSENIUS ANDREAS OTTESEN, OF THISTED, DENMARK.

METHOD OF PRESERVIN G COMESTIBLES.

Specification of Letters Patent.

Application filed November 8, 1912. Serial in. 730,209.

To all whom it may concern: 7

Be it known that I, ANTON JENSENIUS ANDREAS ()TTESEN, of Thisted, Jutland, in the Kingdom of Denmark, -have invented 5 certain new and useful Improvements in Methods of Preserving Comestibles, of which the following is a. specification, reference being bad therein to the accompanying drawing.

This invention refers to a method of freezing or refrigerating juicy or Watery food commodities, such as fish, meat, fruits, 'etc. The invention is based upon the discovery that said food commodities, under certain conditions, can be directly treated with a refrigerating liquid consisting of salts, acids, bases, or other strongly tasting substances which are capable of lowering the melting point, without these substances entering from the refrigerating liquid into the commodities. Under the conditions referred to the food commodities can be frozen superficially or throughout without injuring either their inner or outer natural properties of value.

A better understanding of this invention may be obtained from the following: If a saturated saline solution has a temperature suitable for freezing purposes, say ten degrees below zero, Celsuzs, and if one directly dips into this cold brine watery foodcommodities, such as, for instance, fish of a temperature above the freezing point, say about ten degrees above zero, Celsius, the primarily ensuing effect will be that the surfaces of contact of the fish and the brine react on each other not only thermically but also'osmotically, with the result that the brine absorbs some moisture from the surface of the fish, while the latter absorbs some salt from the brine. Secondly, this salt will diffuse deeper into the skin and flesh of the fish. Thirdly, one or theother of the following two effects will then take place in a more or less marked degree. If the amount of cold present is sufficiently great, owing to the relatively great quantit of the brine, and if the fish is quickly enoug subjected to a sufliciently great quantity of cold, for instance by means of stirring the brine, the quantity of salt primarily and Y secondarily absorbed by the fish will not be sufficient to keep the liquid in the skin and flesh of the fish in a fluid state under the preaches egrees below zero. 'Then .Celsius.

liquid in the skin of the fish will first freeze, and the cold will diffuse into the flesh; but even if all the liquid in the fish freezes to ice with relativel rapidity, the osmotic absorption of salt rom the brine will, nevertheless, not entirely cease, but the salt will continue to penetrate into and diffuse itself into the dry substances of the skin and flesh. If, on the other hand, the quantity of cold present is quite small, or if the fish is not quickly enough subjected to a sufficient quantity of cold, owing to deficient stirring, the quantity of salt absorbed primarily and secondarily by the liquids or tissues of the fish will enable these liquids to keep themselves in a fluid state under the resulting temperature, which will be essentially hi her than ten de ees below zero,

e primary an secondary absorption and diffusion of the salt can, therefore, still be continued, with'the result that the fish, which is refrigerated without stifi ening, will simultaneously become more and more permeated with salt. In practicev there may be imagined many forms 0 transition between these two extremes; but in all cases, a primary absorption of the salt is unavoidable.

The objectof the present invention is to freeze or refrigerate. food commodities direct in brine without the commodities absorbing salt, id test, to make the brine a perfectly indifferent conductor of cold. In order to attain this object, it is necessary to restrain the tendenc of the brine to precipitate or deposit essentiall different manner than the one det, or to absorb moisture and thereby become diluted. In accordance scribed a We Its special feature is a tend--- ency'to form ice which is free from the dissolved salt and notjto combine with moisture with which it is brought into contact,

butv immediately to freeze this i moisture without having entered into osmotic, reciprocal action with it; While drops of water broughtinto contact with a brine of the kind first described'above, even if the temperature of the brine is, for instance, twelve degrees below zero, Celsius, will not fail to mix with the brine and themselves become brme, drops of water coming into contact with the last described,unsaturated and sub use of a floating weight and athermometer Q income between its degree of saturation and its tem-' perature, which maybe ascertained by the placei in a pocket 16, and when there is also produce the strictly, indifi'erent and purely physical conservation of food commodities referred to above. When brine of any other kind is used, however, it is, as aforesaid, impossible to avoid salting, since this takes place as a consequence of osmose, no matter whether the brine is or is not on the crystallizing-point ofthe dissolved salt.

. I will now proceed to illustrate my invention by giving an example of how it may be performed, referring to the drawing in whichv Figure 1 shows a vertical section of a simple kind of apparatus suitable for the performance of this method, Fig.2 is a top View of the same apparatus with the cover removed, and Fig. 3 1s a top view of'an apparatus for continuous treatment of large quantities of comestibles.

The brine is placed in a sufiiciently large, insulated vat or tub 4, Figs. 1 and 2, which contains a cylindrical coil of ipe 5, which, as indicated schematically in 1g. 1, is connected with the circulating pipe 7 of a refrigerating machine 6. In the cylindrical chamber surrounded by the refrigerating coil 5, which chamber is open at top and bottom, there is disposed a vertical shaft 8, which 1s run'from a transmission, or countershaft 9, and which is supplied witha screw propeller or agitator 10, for keeping the brine in motion, and a shoulder 11, which serves as a support for a loose plate 12. This late bears four horizontal arms 13, each of which carries its vertical plate 14, whereby the vat or tub 4: is divided into four uadrant-shaped chambers 15 (see Fig. 2). he brine consists of water containing, for instance,-15% common kitchen salt. By

means of constant supply of cold from the refrigerating: coil 5 the brine is cooled down until me has the surface of the brine. The temperature of the brine will then be about ten to twelve degrees below zero, Celsius. If the brine .contains as much as 20% salt, the temperahim will become lower in a corresponding degree, and will to, for instance, seventeentotwenty degrees below zero,-Celsius. When the brine, whichisconstantly kept in motion in the direction indicated by 'thearrow by of the screw propeller or agitator 10, proper proportion accumulated in the brine a suitable quantity of easily accessible, latent cold in the form of segregated ice, a suitably large quantity of the comestibles in question, for instance fish, in good, moist condition, is placed directly in the brine. I

Depending upon the size of the respective pieces of comestibles, for instance fish, and the desired degree of freezing, they are kept entirely immersed in the brine either for a few'minutes (bait, small fish, and fish of medium size which are to be frozen only superficially), or one half to one hour, or several hours (large cod, salmon, etc., which is to be frozen throughout for long transporta- 'tion). For small fish, or when the fish is not to be frozen throughout, the tempera formed on the .coil and vented, and it will. not occur even if the are again taken u turedoes not need to be lower than about five degrees below zero, Celsius, but the brine must then be diluted in a correspondingdegree, for instance, only containing 8% salt.

Since the brine vat, or tub, is divided into four independent chambers 15 by means of the four plates 14-, it is possible simultaner ously to treat four difierent lots of comestibles, for by turning the cross 12,13, 14, which is loosely suspended on the shaft 8, any one of the chambers'15 can be brought around under an inserting or removing opening 17 in the insulated cover 18.

Owing .to the quantity of warmth contained in the comestibles immersed, the temperature of the brine may gradually rise during the treatment, with the result that the ice floating in the brine and deposited on the refrigerating coil gradually melts entirely or partially. At the first moment, however, just as the brine and the comestibles touch each other, therewill occur an effect similar to that described above with respect to the drops of water, namely, that the moist surface of the fish will be mstantly covered with a coating of ice, without any osmotic by-efl'ect, so that the salt does not gain access even to the skin of the fish. The skin 'is at once osmotically or chemically insulated from the brine. The

enetrationofthe salt into even the supergcial tissues of the fish is once for all prebrine, during the treatment, owing to the the aforesaid proper proportion between the degree of saturation and temperature.

When the comestibles are frozen throughout or are frozen as much as is desired, they out ofthe brine and rinsed, and they w then on being exposed to the air quickly be covered with a coating of. ice or hoar-frost, and in this connection they ma be stored or packed for transportation. en the brinein the refrigerating vat, by a constantly renewed su ly of coldfrom the refrigerating. coil, is ept cooled off to or below i freezing-point, so that new icefis r'med in it, a new quantity of comestibles may be immediately immersed.

By suitably dividing the'vatinto compartments, or by the use of several vats, the pro-' cedure may easily be made continuous, in such a manner that in one vat or compartment of a vat fresh comestibles are constantly immersed, and in another vat or compartment of a vat refrigerated or frozen comestibles are constantly taken out. As an.

-. example, Fig. 3 shows an oblong vat 19,

which,=by means of a partition 20, is di- .vided intotwo oblong chambers 21; along whose long sides refrigerating pipes 22 are disposed in the form of vertical pipe-walls.

Two screw propellers or convey'ersor other form of ag1tators,'23 and 24, the latter of which is.driven from'the former by means of a crossed belt, keep the brine in the vat cireulat' in the direc t-ion indicated by the arrow. number of the baskets 25, intended to contain the comestibles question, are placed-in each cf the chambers 2L and are drawn slowly lengthwise through these chambers. Each time the series of baskets has. been drawn for instance to the left a'dist'ance corresponding to the length of a single basket, there is inserted atvthe right end of the respective chamber- 21 a new basket of fresh comestibles, andat the w left end of saidjchamber the last basket of and the relatively very frozen comestibles is taken out.

For the refrigerating or freezing of a certhin quantity of commodities according to the present method. there is, practically speaking, not required more coldg than is .theoretical'ly'necessary, or (wheii-each lnlogram of commodities is supposed thermically to equal about 0.8 kilogram of water) 0.8 calories for each-degree that the commodity is refrigerated, plus 80 calories for each kilogram 'of frozencommodity. As a consequence of .thetdirect effect of the cold greatrapidity of the treatment,1loss of col by radiation, conduction, etc.,* can be reduced to a minimum.

' Int many cases a refrigerating machine is ecess'ary, for'the cold may be produced according to oneor another of the methods.

generally'in use in work-with refrigerating rmxtures.

Itis is itself nothing a... to freeze comlmodies in an environment whichydoesnot givea-tasteto the commodities, for instance r11 the air. Inindirect freezing in'the a1r,

' m vsuch a manner that the commodities are placed freein thei air, on open shelves, or.

the like,- traverse by streams of refrigeratuid'or frigid r, the commodities are,

in ii dried, an large crystallizaprotected w e in such solution.

of lowering the dissolving-point, it is possible to refrigerate or freeze the comestibles without their absorbing this substance and thereby altering their natural, fresh character. 1 1 l.

Having now particularly described and ascertained the nature of the said invention and in what manner the sameis to be performed, I declare that what I claim is:

1. The process of preserving comestibles, which consists in subjecting them to the di-- rect action of a refrigerating solution whose temperature at the beginning of the treatment is at. or below the freezing oint of the solution and whose strength is elow saturation to thereby initially form a'protective coating of fresh ice on the comestibles and then further refrigerating the comestibles thus'protected while in said solution.

2. The process of preserving moist or wet comestibles, which consists in subjecting them to the direct action of a refrigerating solution whose temperature at .the beginning of the treatment is at or below the freezing point of the solution and whose strength is belew saturation to thereby iming' offresh ice which prevents'penetration of the comestible by the solvent of the solu tion.

3. The process of preserving moist or wet comestibles, which consists in subjecting them to the direct action of a refrigerating solution which is under agitation and whose temperature'at the beginning of the treat- I ment is at or below the point at which ice crystals begin to form. and whose strength is below saturation, said solution under. such conditions initially and instantly forming .tially and instantly form from the surface V moisture of the comestibles a protective'coatfrom the surface moisture of thecomestible 4:.v The process of preserving comestibles, which consists in sub ecting them to the d1- rect action of a refri n peratureat the be is at or below' the e'ezing point of said liq uid, and whose st. h is belowsaturatlcn a protective coatingoffresh ice which pre- ,1

vents penetration of the comestible by the solvent of the solution.

rating liquid consistof a common sa t solutlon whose tem- 'ng of the treatment f I25 to thereby instantly mm a protective coating of fresh ice on the comestible ,and then further vtrefri rating the". comestible thus iao ose temperature at the beginning of the treatment is at ,or below the freezing point of said liquid and whose strength is below saturation, said liquid under said conditions instantlyfiformin from the surface moisture 10 of the .comestib e a protective? coatin fresh ice comestibles,- which consists in sub themto' the direct action of a partia y congealed refri erziting solution whose te reture at t e be 'ng of the treatment 18 at or below the reezing point of thesolu tion; and; whose stren' h is below saturation 2 0 to thereby instantly 01111 from the surface liiuid co'mprisinga common salt solution w of which prevents penetration o the" comestible the salt solution. Y H

'. 6. The process of preserving 'moistor wet ectin'g moisture of the comestible a protective c'oating of fresh ice which revents penetration of thewcomestible by the solvent of .the solutioi which consists in firs ferming afprotective coating of, fresh ice on said comestibles by glunging them into a bath of a refri crating quid comprising a common salt so ution at or belowthe freezing point and then further 'whileinsai refrigerz'ttin liquid;

In testimony, that I c aim the foregoing as my invention, I have signed my name in r presence of two subscribing witnesses; g

7 The process of greserving comestibles;

80 .refrigeratin the comestibles thus protected ANTON .mrs'r'iuus mime orrrsnr.

'Witnessesz g p e HJALMAR Cams Eraser Bonrm,

' Pv HOFMAN BANG. 

